Diodes Incorporated 74LVC244AQ20-13

Overview

74LVC244AQ20-13 from Diodes Incorporated is an octal non-inverting 3-state buffer/line driver in a 20-pin V-QFN4525 package, operating from 1.65V to 3.6V supply, sinking or sourcing ±24 mA at V_CC = 3.0V, with 5.5V-tolerant inputs and IOFF partial power-down protection-used for bus driving and signal isolation in notebook and peripheral interfaces.

For engineers reviewing the 74LVC244AQ20-13 datasheet, 74LVC244AQ20-13 pinout, 74LVC244AQ20-13 application, or 74LVC244AQ20-13 equivalent, key selection criteria include 3-state timing (t_EN ≤ 9.4 ns @ 3.3V), thermal resistance (θ_JA = 67°C/W), input voltage tolerance (up to 5.5V), and QFN-20 footprint compatibility with high-density PCB layouts.

Technical Context

This device implements two independent 4-bit non-inverting buffers, each controlled by a dedicated output-enable (OE) input. Each buffer section drives data unidirectionally from A-inputs to Y-outputs when OE is low; outputs enter high-impedance state when OE is high.

IOFF circuitry actively disables outputs during power-down, preventing backflow current when V_CC = 0V while inputs remain at up to 5.5V. Schmitt-trigger inputs ensure noise immunity on control lines, and all I/O pins support mixed-voltage interfacing between 1.8V, 2.5V, 3.3V, and legacy 5V domains.

Key Specifications

Pinout & Package

V-QFN4525-20 package: 2.5 mm × 4.5 mm × 0.95 mm body, 0.50 mm lead pitch, exposed thermal pad (pin 20 = GND), RoHS-compliant, halogen-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74LVC244APWR and 74LVC244ABQX, the 74LVC244AQ20-13 offers optimal thermal performance (67°C/W) in the smallest footprint (2.5×4.5mm), making it preferred for ultra-thin notebooks and embedded modules where density and power efficiency are prioritized over manual solderability or extended-temp certification.

Availability

74LVC244AQ20-13 is available at Aetrix Electronics and suitable for notebook motherboard design, USB peripheral interface development, SATA storage subsystem integration, and industrial I/O expansion requiring stable component supply and consistent QFN-20 sourcing.

Supply support for 74LVC244AQ20-13 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, energy-efficient components for computing, consumer, and industrial markets.

The 74LVC244A belongs to Diodes' LVC logic family-designed specifically for low-voltage, mixed-signal interfacing in portable and high-density systems where power efficiency, voltage flexibility, and robust ESD performance are essential.

FAQ

What is the maximum clock/data rate supported by the 74LVC244AQ20-13?

The device does not operate on a clock; it is asynchronous. Its propagation delay is 3.8 ns (typical) at 3.3V, supporting data rates up to ~250 Mbps on well-terminated lines. Maximum usable frequency depends on system-level signal integrity, including trace length, termination, and load capacitance-not internal clocking.

Can the 74LVC244AQ20-13 safely interface a 5V microcontroller with a 3.3V FPGA?

Yes-the inputs tolerate up to 5.5V regardless of V_CC, so 5V logic outputs can directly drive A-inputs while V_CC = 3.3V. Outputs swing from 0V to 3.3V, matching FPGA input thresholds. No external level shifters are needed for this direction of translation.

Is the exposed thermal pad on the QFN package required to be soldered to ground?

Yes-the exposed pad (pin 20) is electrically connected to GND and serves as the primary thermal path. It must be soldered to a minimum 100 mm² copper pour tied to the system ground plane using ≥4 thermal vias (0.3 mm diameter) to achieve the specified θ_JA = 67°C/W.

Does the 74LVC244AQ20-13 support hot-swap insertion while V_CC is unpowered?

Yes-its IOFF feature actively disables outputs when V_CC = 0V, limiting input-to-output leakage to ±10 µA even with 5.5V applied to inputs. This prevents back-current damage during live insertion, satisfying JEDEC JESD78 Class I latch-up immunity requirements.